高速公路养护作业占用了既有公路设施，对主线行车安全与效率具有重要影响。为解析四车道公路封闭内侧车道养护作业下的交通流运行特征，提出基于改进元胞自动机的高速公路养护作业区交通流建模与仿真方法。按照《公路养护安全作业规程》（JTG H30—2015）布置养护作业控制区，将主线公路设施划分为警告区、上游过渡区、缓冲区、工作区、下游过渡区、终止区6个交通场景；通过引入纵向安全距离模型和优化横向换道安全条件判定规则，对NaSch跟驰模型和双车道元胞自动机（symmetric two-lane cellular automata, STCA）换道模型进行改进；结合实测数据对模型进行标定，利用MATLAB对养护作业区交通流运行状态进行仿真。结果表明，当交通流密度达到每车道1 550 pcu/h时，将合流起始点设置于距警告区终点1 000 m处、限速值设置为60 km/h、上游过渡区长度设置为160 m，养护作业区交通运行安全与效率的指标最优。

Highway maintenance operations occupy existing road infrastructure and have a significant impact on vehicle traffic safety and efficiency. In order to analyze the traffic flow characteristics during maintenance operations on a four-lane highway when the inner lane is closed, a traffic flow modeling and simulation method based on an improved cellular automaton was proposed. According to the Highway Maintenance Safety Operation Regulations (JTG H30—2015), maintenance operation control zones were established, dividing the mainline highway facilities into six traffic scenarios: warning zone, upstream transition zone, buffer zone, work zone, downstream transition zone, and termination zone. By introducing a longitudinal safety distance model and optimizing the lateral lane-changing safety condition determination rule, the NaSch car-following model and symmetric two-lane cellular automata (STCA) lane-changing model were improved. The model was calibrated using field data, and the traffic flow operating conditions in the maintenance work zone were simulated using MATLAB. The results show that when the traffic flow density reaches 1 550 pcu/h per lane, setting the merging start point 1 000 meters downstream of the warning zone, with a speed limit of 60 km/h and an upstream transition zone length of 160 meters, the traffic flow safety and efficiency indices in the maintenance zone are optimized.